Upgrading a 4G6S to V120D02S

[maverickk]

I am thinking of upgrading my 4G6S, and heard that it is best to change the RX, but on Wow Hobbies website it show both a RX2616V and RX2622V (I have a 2801 Pro TX) listed under the parts section for the V120D02S. What is the difference between the RX2616V and the RX2622V? Is the RX2616V almost as good as the RX2622V?
Thanks

[zadaw]

The 2622V is much better than the 2616V. It is much more stable and 3D capable. Those who have put it in their V120D02, V120D05, and M120D01 have reported a marked increase in stability and performance.

However, I am not sure whether the 2622V will work well with a flybar helicopter. You may need to upgrade to a FBL setup which I am not sure whether it is worth it.

[maverickk]

Thanks Zadaw. If I upgrade I will change out the entire head assembly as well. Just to be clear the current RX in my 4G6S is a RX2610 not the RX2616. Wow list the RX2616 as a RX to use in the V120D02S.

[gabeoravitz]

I hope you know what you're getting into! I attempted to do this upgrade too. I would barely call it an upgrade though. More like building a new heli from the ground up.

Rather than list what is different, I will list what parts are interchangeable on the two helis.

Tail boom
Tail drive shaft (if you want to try to run more power through that carbon fiber shaft isntead of the D02S's metal shaft)
Servos
Skids
Canopy
Main blades

That's pretty much it. You're better off buying an RTF D02S. Not kidding. It's cheaper and easier. I figured this out the hard way. One additional needed shipment of parts at a time.

The head requires the wider main shaft, which requires a new main frame because the bearings are too small. Bigger bearings don't fit in the small holes of the 4G6 frame.

All the gears are bigger. Every single one. NO 4G6 gears will mesh with D02S gears. The motor (and pinion gear) is bigger to turn these bigger gears. This motor requires the bigger 20A ESC. It barely turns with the 4G6 ESC.

Every ball linkage on the heli has bigger ends. Way bigger. Including blade grips, servo horn ball screws, tail servo horn, tail blades rocker, swashplate and tail blade grips.

Theoretically you could leave the 4G6 tail as is, because the shaft and boom going to it are the same (except D02S drive shaft is metal). You are just risking stripping gears with all that power. Also, the tail blades are smaller on the 4G6 and might present a problem with tail authority.

Sorry if I bummed you out haha. Or sorry if you know all this already and are doing it anyway and keeping the tail or whatever. I just figured I'd let you know my experience with this. I just wish someone would have been there to explain this to me before I decided to do it. I actually went INTO Wow Hobbies in person (I live in San Diego) and one of their expert heli pilots assured me it would be simple and only require the head and blade grips. HA! After I bought a buttload of parts, I finally threw in the towel and just bought an RTF and kept all my parts as spares!

Few realize how different this bird is. Every part on it is thicker and tougher. It's a great heli because of this. I crash it over and over and it doesn't break. Not to say it doesn't break; it does. Typtically you'll break servos (unless you do the servo saver mod), tail booms, blade grips, landing skids, and of course tail gears. But these parts take a LOT more punishment than the other 120 size helis. I see a lot of people even confuse it with the V120D02. It's NOT the same heli. If anything, the D02 is MUCH more similar to the 4G6 than the D02S. I would maybe even say that the D02 is the flybarless version of the 4G6. If I were you, I'd considering shooting for converting to a D02 with the rx-2622v from the D02S. Or just buy a D02S RTF and have 2 helis! :-D

Good luck!

[maverickk]

Gabeoravitz - THANK YOU! You did not waste your time, you opened my eyes. Man, I did not realize the extent of the changes needed. You are right, this would be a larger cost, a major headach and a bunch of time. I think I will take your advice and save up and just buy the D02S. Again thanks.

[gabeoravitz]

haha! I'm glad at least someone can benefit from my mistake! Though it IS nice to have all these extra parts and I certainly do love my D02S!

[dbennettya]

Originally Posted by maverickk

Gabeoravitz - THANK YOU! You did not waste your time, you opened my eyes. Man, I did not realize the extent of the changes needed. You are right, this would be a larger cost, a major headach and a bunch of time. I think I will take your advice and save up and just buy the D02S. Again thanks.

Actually I think the simplest mod for you would be to keep the flybar version and get the RX-2622V and just fly it with either the cyclic gyros off or for super stable very low setting. It is fairly easy to just go FBL without going all the way to D02S. See my thread here:

http://www.rcgroups.com/forums/showthread.php?t=1559714

It just depends on how you want to go about it and how many spares you have. I like the old 4G6 because I straighten both main and feathering shafts if needed. I also use Bob's slipper clutch and an aluminum shear pin on the main gear to save parts in a crash.

YMMV, Don

[gabeoravitz]

Don's right. Making the 4g6 flybarless isn't that hard. Doing that, with a 2622v, and the mod's Don described, it'll be a pretty solid heli. Especially if you can straighten your own shafts.

[maverickk]

Don, thaks for the suggestion. I am reading through you RC Goups thread and will take this under consideration. If I just wanted to buy a FBl head to work on my 4G6S could I install a V120D02 or a M120D01 FBL head?
Thanks

[dbennettya]

Originally Posted by maverickk

Don, thaks for the suggestion. I am reading through you RC Goups thread and will take this under consideration. If I just wanted to buy a FBl head to work on my 4G6S could I install a V120D02 or a M120D01 FBL head?
Thanks

Anything other that something similiar to what I did starts to get complex with different main shafts, swash, links, grips and feathering shafts. I wanted to stay pretty much stock using most of the same parts.

Good Luck, Don

[maverickk]

Don, it looks like your mod is pretty simple and I will give this a try. What do you mean by 0-80 hardware? This looks like a 10mm bolt with some nuts which are glued into place.
Thanks

[hjns]

It is pretty easy to upgrade the 4G6S to FBL. Just get the following:

• Get this head. (Strongly recommended)
• Get these long links.
• Optionally get the new plastic blades. (Strongly recommended)

Then change the following:

• Remove the blades from the bladegrips.
• Remove all interlinks from swash to flybar.
• Remove the bladegrips from the old head.
• Remove the main shaft from the frame, leaving the swashplate attached to the servos.
• Remove the old head from the main shaft.
• Add new head to the main shaft.
• Add old bladegrips to the new head (don't forget the washers and the O-rings).
• Insert the mainshaft into the swash and into the frame.
• Attach the two long links to the arms of the bladegrips, through the plastic link guides, onto the swashplate.
• Add the (new) blades.
• Follow the various guides with respect to leveling the swashplate and make sure to have the right pitch angle at the respective throttle inputs.
• Done.

Adding the new V120D02S RX will give you a very nice and stable FBL 4G6.

Comments:

• You can also adjust your current head into a FBL head. However, it means you will have to come up with a solution to keep the long links in phase with the swash and head. The original V120D02 head sucks. Don't buy it. Either DYI or get the Heliworx.de head.
• As mentioned by others, the V120D02S is a completely different beast. Much less vulnerable for damage after crashes. This is mainly due to thicker / plastic components all over the place. Therefore, if you crash often, get a V120D02S.
• The V120D02S plastic blades are really an enormous improvement over the foam / CF / wooden blades. Get them if money allows.

[dbennettya]

Originally Posted by maverickk

Don, it looks like your mod is pretty simple and I will give this a try. What do you mean by 0-80 hardware? This looks like a 10mm bolt with some nuts which are glued into place.
Thanks

0-80 is an SAE size of hardware. So I used 0-80 screws and nuts to make the connections. This approach seems to be working well but it could be improved with ball links.

I am now working on a possible solution using ball joints instead of the screw and nuts but it is much more complicated trying to get the hardware correct. It looks like I'd need a source for 1.2mm x 0.25mm screws and some custom length brass or aluminum threaded spacers and use walkera ball link connectors. The problem is the spacers would have to be custom made from rod and a tap costs about $10. Since my current approach is working I may not implement this.

Good Luck, Don

[maverickk]

HJNS - thanks for the information and links, but when I go to the head link it is in German - do you have a English site?

Don - thanks for the clarification. I think I can make this work if I don't find any off the shelf options.

[hjns]

Not that I know. It is a German shop.

[dbennettya]

Originally Posted by maverickk

HJNS - thanks for the information and links, but when I go to the head link it is in German - do you have a English site?

Don - thanks for the clarification. I think I can make this work if I don't find any off the shelf options.

You can do translate.google.com and copy and paste the verbage in to translate. It didn't work to just translate the web page.

Don

[dbennettya]

Originally Posted by hjns

It is pretty easy to upgrade the 4G6S to FBL. Just get the following:

• Get this head. (Strongly recommended)
• Get these long links.
• Optionally get the new plastic blades. (Strongly recommended)

Then change the following:

• Remove the blades from the bladegrips.
• Remove all interlinks from swash to flybar.
• Remove the bladegrips from the old head.
• Remove the main shaft from the frame, leaving the swashplate attached to the servos.
• Remove the old head from the main shaft.
• Add new head to the main shaft.
• Add old bladegrips to the new head (don't forget the washers and the O-rings).
• Insert the mainshaft into the swash and into the frame.
• Attach the two long links to the arms of the bladegrips, through the plastic link guides, onto the swashplate.
• Add the (new) blades.
• Follow the various guides with respect to leveling the swashplate and make sure to have the right pitch angle at the respective throttle inputs.
• Done.

Adding the new V120D02S RX will give you a very nice and stable FBL 4G6.

Comments:

• You can also adjust your current head into a FBL head. However, it means you will have to come up with a solution to keep the long links in phase with the swash and head. The original V120D02 head sucks. Don't buy it. Either DYI or get the Heliworx.de head.
• As mentioned by others, the V120D02S is a completely different beast. Much less vulnerable for damage after crashes. This is mainly due to thicker / plastic components all over the place. Therefore, if you crash often, get a V120D02S.
• The V120D02S plastic blades are really an enormous improvement over the foam / CF / wooden blades. Get them if money allows.

Henk, those links just send me to the home page. Can you give links that work better?

I think the head we would need is the 001 for 4G6 but it isn't clear what the difference is between 001 and 002 Heliworx heads. I can't tell what links you are referring to either.

Thanks, Don

[hjns]

Hmm..

Rotor head V1.0 - link


The V2 head is rounded, and only fit for V120D02 blade grips. The V1 head is as depicted, and will also fit the original 4G6(S) blade grips.

[dbennettya]

Henk,

Thanks for the clarification. Now I've got to figure out how to improve my design. It seems that my bolt and nut solution is working but has developed a little slop at the bolt and link that I'd rather not have. I'd also like to keep the cost down and use available stock and handmade parts. Maybe I need to add a bushing that can be replaced when worn but the tolerances are pretty tight.

Don

[hjns]

post some pics, and we may be able to offer some suggestions....